Single-storey rear extensions across Northumberland
A single-storey extension in Northumberland starts with the right design and the right approval route. We take care of both, then build it with our own project management.
- Guide priceFrom £19,000 inc VAT
- PlanningOften permitted development (3–4 m), or prior approval up to 6–8 m
- Towns covered7
- Site visitFree, no obligation
Towns in Northumberland
What is included
- Walls, steel beams and the new opening into the house
- Planning route checked and the right approval obtained
- Flat or pitched roof, rooflights or lantern
- Foundations, drainage and groundworks
How much does a single-storey extension cost in Northumberland?
For Northumberland we adjust our national guide rates by ×0.91, the factor we use for North East England. Figures include VAT; your written quote after the survey replaces them.
Typical rates in Northumberland: £1,590 to £3,090 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 4 m 12 m² | £19,000 – £22,500 | £22,000 – £28,500 | £28,000 – £37,500 |
| 4 m × 5 m 20 m² | £31,500 – £37,500 | £37,000 – £47,500 | £47,000 – £62,000 |
| 5 m × 6 m 30 m² | £47,500 – £56,000 | £55,500 – £71,000 | £70,500 – £93,000 |
Want a range for your exact size? The guide-price tool takes about a minute.
Planning and approvals in Northumberland
In England a single-storey rear extension can usually go up to 3 m beyond the original rear wall of a semi-detached or terraced house, or 4 m on a detached house, without a planning application, provided it is no more than 4 m high, keeps eaves to 3 m within 2 m of a boundary and, with other buildings, covers no more than half the land around the original house. The larger home extension prior approval scheme raises those depths to 6 m and 8 m, with neighbours notified and a 42-day decision.
The planning position for a specific Northumberland address depends on its history and any designations, which is why we check it at the first visit.
Building regulations approval is separate from planning. In England you can use the council's building control team or a registered building control approver; a full plans application gets the drawings checked before work starts, and the inspector signs the work off with a completion certificate.
If the work involves a shared wall, building on the boundary, or digging foundations within 3 m (sometimes 6 m) of a neighbour's building, the Party Wall etc. Act 1996 applies and notice must be served before work starts: two months for work to a party wall, one month for new walls on the boundary and for excavations.
Applications are decided by the local planning authority (your district, borough or unitary council).
Covering Northumberland
Towns we cover in Northumberland include Blyth, Cramlington, Ashington, Bedlington, Morpeth, Hexham, Alnwick. The North East has many brick terraces, colliery-era housing and post-war semis, with rear extensions and kitchen extensions the most common requests.
Our process, step by step
Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.
Free site visit
First, a site visit: we look at the house, garden, access and drains and listen to what you need.
Design and approvals
Drawings are prepared and agreed with you, then submitted for the right planning route and building regulations approval.
Fixed written price
The price is fixed in writing once the design is settled, with a clear programme and payment stages.
Build and sign-off
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Single-storey extension questions answered
Do I need building regulations approval in Northumberland?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Will my neighbours in Northumberland be involved?
If a planning application or prior approval is needed, the council notifies neighbours. If the work is on or near a shared boundary, party wall notices may also be needed.
How long does a single-storey extension take to build in Northumberland?
On site, typically 10 to 16 weeks once approvals are in place. Before that, allow 4–12 weeks design and approvals.
Can I stay in the house during the build?
Usually yes. Most of the work happens outside until the final weeks, when we open the rear wall. We plan that stage carefully and seal the opening with a temporary screen to keep dust down.
How much does a single-storey extension cost per square metre?
Our guide range is about £1,590 to £3,090 per m² including VAT, depending on specification. A standard-spec 4 m × 5 m room usually lands at £37,000 to £47,500 in Northumberland, plus design and council fees.
Book a free site visit in Northumberland
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.